Termiticidal Activity of Libidibia ferrea var. ferrea and of the Association With Isaria spp. Against Nasutitermes corniger

Nasutitermes corniger (Motschulsky) is an urban termite pest that is controlled by chemical applications. We investigated the effect of the association of Isaria farinosa (Holm: Fries) Fries, I. fumosorosea (Wize) Brown & Smith, and I. javanica (Frieder & Bally) Samson & Hywell-Jones with the extracts of Libidibia ferrea var. ferrea (Mart. Ex Tul.) L. P. Queiroz in the control of N. corniger. The following experiments were performed: the toxicity of aqueous and methanolic extracts on the biological aspects of fungi, action of extracts on workers and soldiers, and fungus-extract combination on workers of termite. The aqueous extracts of the leaves and pods of L. ferrea var. ferrrea were more efficient than the methanol extracts, demonstrating termiticide activity at 10, 25, 50, 100, and 200 mg mL-1, with 100% worker mortality after the third and fourth days and 100% soldier mortality by the third through sixth day. Lethal concentrations (LC50) varied from 0.624 to 0.710 mg mL-1 for workers and from 0.146 to 1.410 mg mL-1 for soldiers. The extracts were compatible with the fungal strains at the lowest concentrations. Associations of the extracts with I. farinosa ESALQ1355 demonstrated efficient control of termite workers. The results demonstrate that L. ferrea var. ferrrea extracts, either alone or in association with I. farinosa ESALQ1355, functioned in the in vitro control of N. corniger, representing a viable alternative to be further tested in controlling those termites in urban areas.